Recently I’ve been doing a lot more work in SharePoint, specifically 2010. As anyone who has worked in SharePoint for any amount of time knows it has a lot of quirks!   One that recently has been giving me some troubles is the error message “Unable to delete content type. The content type is in use.” This was troubling to me because   I knew I had deleted all the lists and everything that was referencing the content type.

Finally after digging around on the internet I came across a solution:

After you’ve deleted all the lists that you know of you need to also delete them from the Site Collection recycle bins as well. You’ll need to be Site Collection Admin in order to do the following.

  1. Navigate to the root site collection’s settings.aspx page.
  2. Click on Recycle Bin under the “Site Collection Admin" section.
Site Collection Recycle Bin
  1. Delete anything that referenced the content type (i.e. – the list) from the “End User’s Recycle Bin items”.
  2. Click on “Deleted from end user Recycle Bin” and delete anything that referenced the content type (i.e. – the list).  
Site Collection Recycle Bin

This helped me resolve the Content Type in use issue. Hope it helps!